Computerized physician order entry (CPOE) is increasingly being recognized as a necessary system for enhancing patient safety in hospitals, yet it is neither widespread nor heavily used in the U.S. We have shown through previous research that the reasons involve a complex web of technical, organizational, and contextual issues. This competing continuation proposal outlines four aims, within a Diffusion of Innovations (DOI) theory framework, designed to discover more about clusters of functionalities at different levels of sophistication, called infusion, of CPOE and the unintended consequences that may be associated with each level so that in the future, these consequences can be avoided or effectively managed. RESEARCH QUESTIONS . What are the common levels of infusion/functionalities of CPOE? . What are the unintended consequences of CPOE and how have those with relevant experience successfully managed such unintended consequences? . What is the relationship between infusion and consequences? . Can we discover enough about preventive strategies and solutions for unintended consequences so that a useful toolkit can be developed and disseminated? SPECIFIC AIMS AIM 1: Develop an expert-derived schema of unintended consequences already faced by experts. Convene a panel of experts to identify unintended consequences of CPOE (such as CPOE-caused medical errors), strategies for managing them, and clusters of functionality that might indicate infusion levels of CPOE. AIM 2: Study the implementation of CPOE at nine sites in the U.S. in sufficient depth to identify relationships between infusion levels and unintended consequences. Using qualitative techniques, a multi disciplinary team will interview and observe clinicians, information technology personnel, and leaders at selected sites (selection based on location, ownership, affiliation and age of system). The expert-derived schema will serve as a guide for this effort. AIM 3: Survey U.S. hospitals to discover their levels of infusion and their experiences with unintended consequences. Survey hospitals in the U.S. that have CPOE for more information about infusion, related unintended consequences, and solutions using the data gathered from Aim 1 and 2. AIM 4: Develop, refine, and disseminate a toolkit for preventing and overcoming unintended consequences. Data from Aims 1,2 and 3 will be analyzed and presented to the expert panel at a second conference. The panel will develop a toolkit comprised of an agreed-on list of unintended consequences that might be expected at each infusion level and recommended prevention strategies and solutions. The toolkit will be modified after the conference by these experts and published in media to reach a broad audience, including the World Wide Web.